Earth boring machines have existed for quite some time now, and these machines which are most efficient comprise specially designed mobile trucks provided with outriggers and the like to provide the greatest control in boring at any specified angle.
The following patents reflect the state of the art as far as applicant is aware:
U.S. Pat. No. 1,319,259 Adams PA1 U.S. Pat. No. 1,376,045 Skott PA1 U.S. Pat. No. 2,474,981 McCardell PA1 U.S. Pat. No. 2,602,637 Talbot PA1 U.S. Pat. No. 3,148,739 Mattingly et al PA1 U.S. Pat. No. 3,306,372 Struve PA1 U.S. Pat. No. 3,714,990 Tomik
Of these, Mattingly et al teach the use of a boring auger which is capable of angulation relative to a vertical plane, but clearly is not for use with hydraulics of a tractor.
Tomik provides an auger plow using a three-point linkage (10) plus lower arms (11) to provide the necessary support. His structure is essentially more complex than that which defines the instant application, and further this patent is silent on the precise and specific drilling concepts which form the basis of the present invention.
The remaining references, while showing the state of the art further, merely provide isolated elements which may share a coincidental similarity with certain aspects of the instant application, but none of these references either teach or render obvious the apparatus according to the instant application.